private void TopoSort(Node cur)
{
if (_states.TryGetValue(cur, out var b))
{
if (!b)
{
throw new InvalidOperationException("A cycle has been encountered");
}
return;
}
_states[cur] = false;
for (var i = 0; i < cur.Outgoing.Count; i++)
{
TopoSort(cur.Outgoing[i]);
}
_states[cur] = true;
SortedNodes.Add(cur);
}
public override void AddEdge(Node src, Node dest)
{
for (; SortedNodes.Count < Nodes.Count;)
{
SortedNodes.Add(Nodes[SortedNodes.Count]);
}
if (src.Index < dest.Index)
{
src.Outgoing.Add(dest);
dest.Incoming.Add(src);
return;
}
_deltaPlus.Clear();
Dfs(dest, _deltaPlus, n => n.Outgoing, dest.Index, src.Index);
_deltaMinus.Clear();
Dfs(src, _deltaMinus, n => n.Incoming, dest.Index, src.Index);
_deltaPlusList.Clear();
_deltaPlusList.AddRange(_deltaPlus.OrderBy(node => node.Index));
_deltaPlus.IntersectWith(_deltaMinus);
if (_deltaPlus.Count > 0)
{
throw new InvalidOperationException("The edge to be added would introduce a cycle");
}
src.Outgoing.Add(dest);
dest.Incoming.Add(src);
_deltaMinusList.Clear();
_deltaMinusList.AddRange(_deltaMinus.OrderBy(node => node.Index));
_merged.Clear();
int f = 0, s = 0;
while (f < _deltaPlusList.Count && s < _deltaMinusList.Count)
{
if (_deltaPlusList[f].Index < _deltaMinusList[s].Index)
{
_merged.Add(_deltaPlusList[f].Index);
f++;
}
else
{
_merged.Add(_deltaMinusList[s].Index);
s++;
}
}
for (; f < _deltaPlusList.Count; f++)
{
_merged.Add(_deltaPlusList[f].Index);
}
for (; s < _deltaMinusList.Count; s++)
{
_merged.Add(_deltaMinusList[s].Index);
}
var cEntry = 0;
for (int q = 0; q < _merged.Count; q++)
{
var cNode = cEntry < _deltaMinusList.Count ? _deltaMinusList[cEntry] : _deltaPlusList[cEntry - _deltaMinusList.Count];
cEntry++;
SortedNodes[_merged[q]] = cNode;
}
for (int q = 0; q < _merged.Count; q++)
{
SortedNodes[_merged[q]].Index = _merged[q];
}
}
